The invention relates to a device for controlling the opening and shutting movement of sliding elevator doors.
In a conventional elevator installation, the `open` and `shut` sliding movements of the landing door are brought about when the elevator compartment draws level with the landing at each floor; the actual movement derives from that of the door of the compartment, with which a mechanical linkage is established at the moment of opening and closing. Such a linkage incorporates a special catch component, attached either to the outermost section of a telescopic type compartment door, or to the single panel in a simple door assembly, that engages a corresponding latching system fastened to the inside of the landing door. The latching system will normally consist in a pair of parallel rollers or pins, which are disposed horizontally and set apart at a distance such as will allow the catch to locate between them during normal ascent and descent of the elevator car.
Clearly enough, the two rollers need to project from the face of the landing door, as well as from the relative internal wall of the elevator shaft, and in order to avoid their unwarranted contact with the elevator car, a certain minimum clearance must be left between the landing threshold and the compartment threshold, or the outermost surface of the car. The distance in question will not be less than 25 . . . 30 mm (1-11/2")in most instances, and is the source of a number of drawbacks arising from the gap created between the landing and compartment thresholds. Transit into and out of the elevator is rendered problematic by the very wideness of the gap, especially with trolleys having small diameter wheels or casters.
Accordingly, the object of the invention is to overcome the drawbacks mentioned above.